1. Technical Field
The present invention relates to an electro-optical device such as a liquid crystal device which includes a thin film transistor as a switching element disposed in each of pixels on an element substrate, for example, and an electronic apparatus such as a liquid crystal projector.
2. Related Art
In a liquid crystal device which is an example of the electro-optical device, alignment of an electro-optical material interposed between a pair of substrates is current-controlled by writing an image signal to pixel electrodes in synchronization with an ON/OFF operation of the respective pixel electrodes by TFTs functioning as a switching element. This switching element, a wiring, or the like is formed so as to have a laminated structure on a substrate.
Reduction of black irregularity in an image display unit (that is, improvement in a contrast) or prevention of deterioration in a pixel lifetime was designed by additionally forming a holding capacitor so as to have a laminated structure and adjusting the capacitance value of the holding capacitor in each of the pixels. Specifically, there was suggested a technique for forming a laminated structure in which an existing conductive layer such as a wiring also functions as a capacitor electrode and for effectively forming the holding capacitor while suppressing complexity of the laminated structure caused due to addition of the holding capacitor (see JP-A-10-39336, JP-A-2004-109974, and JP-A-2006-189898).
There is parasitic capacitance or capacitance coupling between a plurality of conductive layers in the laminated structure. Accordingly, in the respective conductive layers as wirings or electrodes, when voltage such as signal voltage or power voltage is applied to the respective conductive layers or when current such as signal current or power current flows, an electronic noise occurs between the plurality of conductive layers. In particular, when an image signal in an image signal line is affected by the electronic noise, the image signal may be distorted and the quality of a display image may thus deteriorate. Therefore, a more serious problem is caused. As a method of reducing the electronic noise, a method of increasing the thickness of an inter-layer insulating film interposed between the plurality of conductive layers can be taken into consideration. However, a basic concept of miniaturization of the electro-optical device may not be realized